Abstract:

An imprint process of a thermosetting material is described, comprising:
providing a mold including pattern structures, wherein convex portions
and concave portions of the pattern structures are covered with a
transferred material layer; providing a substrate, wherein a
thermosetting material layer and a sacrificial layer cover the substrate
in sequence; performing an imprint step to transfer the transferred
material layer on the convex portions onto a first portion of the
sacrificial layer; etching a second portion of the sacrificial layer and
the underlying thermosetting material layer by using the transferred
material layer as a mask; and performing a wet stripping step by using a
stripper to completely etch the sacrificial layer and the overlying
transferred material layer, wherein the stripper has a first etching rate
and a second etching rate to the thermosetting material layer and the
sacrificial layer respectively, and a ratio of the second etching rate to
the first etching rate is greater than or equal to 30.

Claims:

1. An imprint process of a thermosetting material, comprising:providing a
mold including a pattern structure, wherein the pattern structure
comprises a plurality of concave portions and a plurality of convex
portions;forming a transferred material layer on the convex portions and
the concave portions;providing a substrate, wherein a surface of the
substrate is covered with a thermosetting material layer and a
sacrificial layer in sequence;performing an imprint step to transfer the
transferred material layer on the convex portions onto a first portion of
the sacrificial layer and to expose a second portion of the sacrificial
layer;etching the second portion of the sacrificial layer and a second
portion of the underlying thermosetting material layer to remain the
first portion of the sacrificial layer and a first portion of the
underlying thermosetting material layer by using the transferred material
layer as a mask; andperforming a wet stripping step by using a stripper
to completely etch the first portion of the sacrificial layer and to lift
off the overlying transferred material layer, wherein the stripper has a
first etching rate and a second etching rate to the thermosetting
material layer and the sacrificial layer respectively, and a ratio of the
second etching rate to the first etching rate is greater than or equal to
30.

2. The imprint process of a thermosetting material according to claim 1,
wherein a material of the transferred material layer is metal, oxide or a
dielectric material.

3. The imprint process of a thermosetting material according to claim 1,
wherein a material of the transferred material layer is chromium.

4. The imprint process of a thermosetting material according to claim 1,
wherein a material of the sacrificial layer is polymethylmethacrylate
(PMMA).

5. The imprint process of a thermosetting material according to claim 4,
wherein the stripper is acetone.

6. The imprint process of a thermosetting material according to claim 1,
whereina material of the thermosetting material layer is RN-1349
polyimide provided by Nissan Chemical Industries;a material of the
sacrificial layer is polymethylmethacrylate (PMMA); anda material of the
stripper is TAIMAX acetone provided by Taiwan Maxwave Co., Ltd.

7. The imprint process of a thermosetting material according to claim 1,
whereina material of the thermosetting material layer is RN-1349
polyimide provided by Nissan Chemical Industries;a material of the
sacrificial layer is photoresist S1818 provided by Shipley Company,
L.L.C., Marlborough, Mass., U.S.A.; anda material of the stripper is
acetone.

8. The imprint process of a thermosetting material according to claim 1,
whereina material of the sacrificial layer is PMMA 950K A6 provided by
MicroChem Corp., Newton, Mass., U.S.A.; anda material of the stripper is
TAIMAX acetone provided by Taiwan Maxwave Co., Ltd.

9. The imprint process of a thermosetting material according to claim 1,
whereina material of the sacrificial layer is photoresist S1818 provided
by Shipley Company, L.L.C., Marlborough, Mass., U.S.A.; anda material of
the stripper is TAIMAX acetone provided by Taiwan Maxwave Co., Ltd.

10. The imprint process of a thermosetting material according to claim 1,
wherein a material of the stripper is TAIMAX acetone provided by Taiwan
Maxwave Co., Ltd.

11. The imprint process of a thermosetting material according to claim 1,
wherein the transferred material layer is formed by a thermal evaporation
method, an e-beam evaporation method, a chemical vapor deposition method
or a physical vapor deposition method.

12. The imprint process of a thermosetting material according to claim 1,
wherein the ratio of the second etching rate to the first etching rate is
greater than or equal to 40.

13. The imprint process, of a thermosetting material according to claim
12, wherein the ratio of the second etching rate to the first etching
rate is greater than or equal to 50.

14. The imprint process of a thermosetting material according to claim 12,
wherein the step of etching the second portion of the sacrificial layer
and the second portion of the thermosetting material layer is performed
by a dry etching process.

15. The imprint process of a thermosetting material according to claim 14,
wherein the dry etching process is a reactive ion etching (RIE) process
or an inductively coupled plasma (ICP) ion etching process.

16. The imprint process of a thermosetting material according to claim 15,
wherein the dry etching process uses oxygen as a main reactive gas.

17. The imprint process of a thermosetting material according to claim 1,
wherein a material of the mold is ethylene tetrafluoroethylene provided
by DuPont Company.

18. The imprint process of a thermosetting material according to claim 1,
between the step of providing the mold and the step of forming the
transferred material layer, further comprising forming an anti-stick
layer on the convex portions and the concave portions of the mold.

19. The imprint process of a thermosetting material according to claim 1,
wherein the imprint step further comprises:pressing the transferred
material layer on the convex portions of the pattern structure of the
mold on the sacrificial layer on the substrate;performing a baking step
on the sacrificial layer to dry the sacrificial layer; andremoving the
mold.

20. The imprint process of a thermosetting material according to claim 19,
wherein the baking step is performed at substantially 95.degree. C. in
substantially five minutes.

21. The imprint process of a thermosetting material according to claim 1,
after the wet stripping step, further comprising:rinsing the substrate
and the first portion of the thermosetting material layer by deionized
water; andperforming a heating and baking step on the substrate and the
first portion of the thermosetting material layer.

22. The imprint process of a thermosetting material according to claim 21,
wherein the heating and baking step is performed under substantially
100.degree. C. for substantially three minutes.

23. The imprint process of a thermosetting material according to claim 1,
wherein a material of the thermosetting material layer is polyimide (PI)
or polyethersulfone (PES).

Description:

[0002]The present invention relates to an imprint process, and more
particularly to an imprint process of a thermosetting material.

BACKGROUND OF THE INVENTION

[0003]A thermosetting material, such as polyimide (PI), is a material with
high heat resistance, a great mechanical property, a superior optical
property and a low dielectric constant, so that the thermosetting
material has been widely applied in flexible printed circuit (FPC)
boards, electronic packages, optical waveguides, alignment films of
liquid crystal displays (LCD) and microfluidic devices. In the
application, the thermosetting material typically needs to be patterned
by a pattern definition technology to form the desired pattern structure
for use.

[0004]Several technologies, such as laser machining technology,
conventional photolithography technology, new photolithography
technology, and nano-imprint technology including, for example soft
imprint technology and hot-embossing technology, have been developed to
pattern the thermosetting material. When the laser machining technology
patterns the thermosetting material, the laser directly irradiates the
thermosetting material layer through a mask to remove a portion of the
thermosetting material layer to complete the thermosetting material
pattern structures. However, when the laser machining technology patterns
the thermosetting material, irradiation of many laser shots is required,
so that the process is time-consuming and consumes large amounts of laser
energy, thereby increasing the cost. Moreover, due to the size of the
laser beam and the optical diffraction limit, the laser machining
technology cannot produce the pattern with too small size, such as the
thermosetting material pattern structures with the nanometer scale.

[0005]When the conventional photolithography technology is used to pattern
a thermosetting material layer, a photoresist layer is firstly coated on
the thermosetting material layer, the photoresist layer is patterned by
the exposure and development technology, and then the thermosetting
material layer is etched with tile patterned photoresist layer as the
etching mask to complete the thermosetting material pattern structures.
However, due to the wavelength limit of the exposure light source, the
feature size of the thermosetting material pattern strictures produced by
the conventional photolithography technology has a limit, so that the
pattern structures with a smaller size cannot be produced.

[0006]When the new photolithography technology is used to pattern the
thermosetting material, a photosensitive thermosetting material is
needed, the bonding link in parts of directions of the thermosetting
material is destroyed by directly using the light source, such as deep
ultraviolet, and the exposed thermosetting material layer is developed to
complete the pattern structures of the thermosetting material. However,
the surface roughness of the thermosetting material pattern structure
formed by the new photolithography technology is poor, there still exists
many issues in the positive tone and negative tone photosensitive
thermosetting materials, such as that the adjustment of the ingredients
of the material is difficult, and the control of the process parameters
and the machining precision of the thermosetting material is difficult to
result in the poor fidelity and the reliability of pattern transferring.
In addition, similarly, due to the wavelength limit of the exposure light
source, the new photolithography technology cannot produce the
thermosetting material pattern structures with a smaller size.
Furthermore, the negative tone photosensitive thermosetting material is
swelling after the developing process, so that the fidelity of the
pattern transferring is further decreased.

[0007]When the soft nanoimprint technology is used to pattern the
thermosetting material, such as polyimide, and the imprint mold is
pressed into the liquid poly(amic acid) (PAA) that has not been heated to
form the solid polyimide, it is easy for bubbles to form between the
pattern structures of the imprint mold and the liquid poly(amic acid)
after heating, and these bubbles are formed on the surface of the
polyimide. Therefore, the surface of the pattern structures of the
thermosetting material formed by the soft nanoimprint technology has many
holes, so that the surface roughness of the thermosetting material
pattern structures is poor, and the mechanical strength of the
thermosetting material pattern structures is reduced. Moreover, when the
liquid poly(amic acid) is heated to solidify the liquid poly(amic acid)
to form the polyimide before the mold is removed, the solvent of the
poly(amic acid) is evaporated, so that the volume of the thermosetting
material pattern structures is decreased to lower the fidelity of the
pattern transferring.

[0008]When the hot embossing nanoimprint technology is used to pattern the
thermosetting material, the imprint temperature needs to be raised to
more than the glass transition temperature (Tg) 300° C. of the
thermosetting material. In addition, due to the heat, the remaining
thermal stress, the expansion and the shrink effects occur on the mold
and the substrate simultaneously, thereby seriously affecting the
substrate material and the size of the thermosetting material pattern
structures to reduce the reliability of the pattern transferring.

SUMMARY OF THE INVENTION

[0009]Therefore, one objective of the present invention is to provide an
imprint process of a thermosetting material, which can accurately
transfer a pattern on an imprint mold to a thermosetting material layer,
thereby effectively increasing the accuracy and the reliability of the
pattern transferred to the thermosetting material layer.

[0010]Another objective of the present invention is to provide an imprint
process of a thermosetting material, which can successively define the
pattern of the thermosetting material with low thermal budget and under
relatively lower temperatures compared with the hot embossing nanoimprint
process, thereby reducing the process cost and preventing the feature
size of the transferred pattern of the thermosetting material from being
distorted. Furthermore, the remaining thermal stress formed on the
substrate and the thermosetting material layer due to high temperature
can be decreased, and the substrate and the thermosetting material layer
can be prevented from being damaged.

[0011]According to the aforementioned objectives, the present invention
provides an imprint process of a thermosetting material, comprising:
providing a mold including a pattern structure, wherein the pattern
structure comprises a plurality of convex portions and a plurality of
concave portions; forming a transferred material layer on the convex
portions and the concave portions; providing a substrate, wherein a
surface of the substrate is covered with a thermosetting material layer
and a sacrificial layer in sequence; performing an imprint step to
transfer the transferred material layer on the convex portions onto a
first portion of the sacrificial layer and to expose a second portion of
the sacrificial layer; dry etching the second portion of the sacrificial
layer and a second portion of the underlying thermosetting material layer
to remain the first portion of the sacrificial layer and a first portion
of the underlying thermosetting material layer by using the transferred
material layer as a mask; and performing a wet stripping step by using a
stripper to completely etch the first portion of the sacrificial layer
and to lift off the overlying transferred material layer, wherein the
stripper has a first etching rate and a second etching rate to the
thermosetting material layer and the sacrificial layer respectively, and
a ratio of the second etching rate to the first etching rate is greater
than or equal to 30.

[0012]According to a preferred embodiment of the present invention, the
material of the sacrificial layer may be PMMA 950K A6 provided by
MicroChem Corp., Newton, Mass., U.S.A. or photoresist S1818 provided by
Shipley Company, L.L.C., Marlborough, Mass., U.S.A., the stripper may be
acetone, such as TAIMAX acetone provided by Taiwan Maxwave Co., Ltd.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]The foregoing aspects and many of the attendant advantages of this
invention are more readily appreciated as the same become better
understood by reference to the following detailed description, when taken
in conjunction with the accompanying drawings, wherein:

[0014]FIGS. 1A through 1H are schematic flow diagrams showing an imprint
process of a thermosetting material in accordance with a preferred
embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015]FIGS. 1A through 1H are schematic flow diagrams showing an imprint
process of a thermosetting material in accordance with a preferred
embodiment of the present invention. In an exemplary embodiment, when the
imprint process of a thermosetting material is performed, a mold 100 may
be provided to perform the imprint process. A pattern structure 104 is
set in a surface 102 of the mold 100, wherein the pattern structure 104
comprises a plurality of concave portions 108 and a plurality of convex
portions 106. The feature size of the pattern structure 104 may be
micrometer scale or nanometer scale. Next, such as shown in FIG. 1A, an
anti-stick layer 110 is selectively formed to cover the pattern structure
104 of the mold 100 by, for example, a thermal evaporation method,
wherein the anti-stick layer 110 includes two portions 110a and 110b, the
portion 110a of the anti-stick layer 110 covers on bottoms of the concave
portions 108 of the pattern structure 104, and the portion 110b of the
anti-stick layer 110 covers on top surfaces of the convex portions 106 of
the pattern structure 104. In another exemplary embodiment, when the
material of the mold 100 itself has an anti-stick property, such as
ethylene tetrafluoroethylene [--(C2H4-C2F4)-] provided by DuPont Company,
the anti-stick layer 110 does not need to be formed additionally.

[0016]Next, such as shown in FIG. 1B, a transferred material layer 112 is
formed on the anti-stick layer 110 by using, for example a thermal
evaporation method, an e-beam evaporation method, a chemical vapor
deposition method or a physical vapor deposition method cooperating with
a typical pattern definition technique, wherein the transferred material
layer 112 also includes portions 112a and 112b, the portions 112a of the
transferred material layer 112 are located on the portion 110a of the
anti-stick layer 110 within the concave portions 108 of the pattern
structure 104, and the portions 112b of the transferred material layer
112 are located on the portion 111b of the anti-stick layer 110 on the
top surfaces of the convex portions 106 of the pattern structure 104. In
another exemplary embodiment, when the material of the mold 100 itself
has an anti-stick property and the anti-stick layer 110 is not formed,
the transferred material layer 112 directly covers the pattern structure
104 of the mold 100, wherein the portions 112a of the transferred
material layer 112 are directly located on die bottoms of the concave
portions 108 of the pattern structure 104, and the portions 112b of the
transferred material layer 112 are directly located on the top surfaces
of the convex portions 106 of the pattern structure 104. The material of
the transferred material layer 112 may be metal, oxide or a dielectric
material. In one embodiment, the material of the transferred material
layer 112 may be chromium (Cr). In another embodiment, the material of
the transferred material layer 112 may be a dielectric material and
oxide, such as silicon dioxide (SiO2). By disposing the anti-stick
layer 110 or adopting the mold 100 having an anti-stick property, the
portions 112b of the transferred material layer 112 on the convex
portions 106 of the mold 100 can be successively separated from the
convex portions 106 of the mold 100.

[0017]Simultaneously, a substrate 114 desired to be imprinted is provided,
wherein the substrate 114 is preferably composed of a material that can
resist the etching of the stripper 130 (referring to FIG. 1G). The
material of the substrate 114 may be, for example, silicon wafer, glass,
quartz or metal. A thermosetting material layer 118 is formed to cover a
surface 116 of the substrate 114 by, for example, a physical vapor
deposition method, a chemical vapor deposition method or a coating
method. In some embodiments, the material of the thermosetting material
layer 118 may be, for example, polyimide or polyethersulfone (PES),
wherein each polyimide and polyethersulfone is a material having a high
glass transition temperature. In an exemplary embodiment, the material of
the thermosetting material layer 118 may be RN-1349 polyimide provided by
Nissan Chemical Industries. Next, the thermosetting material layer 118
may be baked to dry the solvent in the thermosetting material layer 118.
Then, such as shown in FIG. 1C, a sacrificial layer 120 is formed to
cover the thermosetting material layer 118 by, for example, a deposition
method or a coating method. In an exemplary embodiment, the material of
the sacrificial layer 120 may be polymethylmethacrylate (PMMA) or
photoresist S1818 provided by Shipley Company, L.L.C., Marlborough,
Mass., U.S.A. The material of the sacrificial layer 120 also may be PMMA
950K A6 provided by MicroChem Corp., Newton, Mass., U.S.A. The choice of
the materials of the thermosetting material layer 118 and the sacrificial
layer 120 is in relation to the stripper 130 (referring to FIG. 1G),
wherein the stripper 130 has two different etching rates to the
thermosetting material layer 118 and the sacrificial layer 120
respectively, and the etching rate of the stripper 130 to the sacrificial
layer 120 is much larger than that of the stripper 130 to the
thermosetting material layer 118. Therefore, when the sacrificial layer
120 is completely removed by the stripper 130, the thermosetting material
layer 118 may hardly be etched by the stripper 130 and is kept. In an
exemplary embodiment, the ratio of the etching rate of the stripper 130
to the sacrificial layer 120 to the etching rate of the stripper 130 to
the thermosetting material layer 118 may be preferably larger than or
equal to 30, more preferably be larger than or equal to 40, and further
more preferably be larger than or equal to 50.

[0018]Next, referring to FIG. 1D, an imprint step is performed, wherein
the surface 102 of the mold 100 is oppositely pressed on the surface 116
of the substrate 114 to press the portions 112b of the transferred
material layer 112 on the convex portions 106 of the pattern structure
104 of the mold 100 on the liquid status of the sacrificial layer 120 on
the substrate 114 and contact with the sacrificial layer 120. After the
portions 112b of the transferred material layer 112 on the mold 100 are
pressed on the sacrificial layer 120 on the substrate 114, the
sacrificial layer 120 is baked at substantially 95° C. in
substantially five minutes to dry the sacrificial layer 120. After the
temperature is lowered to room temperature, the mold 100 is removed from
the sacrificial layer 120. At this time, the convex portions 106 of the
pattern structure 104 of the mold 100 are covered with the anti-stick
layer 110 to make the anti-stick layer 110 be located between the surface
102 of the mold 100 and the transferred material layer 112, or the mold
100 itself has an anti-stick property, so that the portions 112b of the
transferred material layer 112 on the convex portions 106 of the pattern
structure 104 of the mold 100 can be successfully separated from the mold
100 to transfer to the surface of the sacrificial layer 120 to complete
the imprint step. After the imprint step is completed, the portions 112b
of the transferred material layer 112 are only transferred to a first
portion 122 of the sacrificial material layer 120, and a second portion
124 of the sacrificial layer 120 is exposed, such as shown in FIG. 1E.

[0019]Next, referring to FIG. 1F, the second portion 124 of the
sacrificial layer 120 uncovered by the portions 112b of the transferred
material layer 112 and the portion of the thermosetting material layer
118 underlying the second portion 124 are removed until a portion of the
surface 116 of the substrate 114 underlying the second portion 124 of the
sacrificial layer 120 is exposed, and the first portion 122 of the
sacrificial layer 120 and a first portion 126 of the thermosetting
material layer 118 underlying the first portion 122 are maintained. In
another embodiment, according to the difference of the applications of
the products, the removal step may only remove the second portion 124 of
the sacrificial layer 120 and a portion of the thermosetting material
layer 118 underlying the second portion 124 of the sacrificial layer 120
to keep the first portion 122 of the sacrificial layer 120, the other
portion of the thermosetting material layer 118 underlying the second
portion 124 of the sacrificial layer 120, and the first portion 126 of
the thermosetting material layer 118 underlying the first portion 122.
Accordingly, the surface 116 of the substrate 114 underlying the second
portion 124 of the sacrificial layer 120 is not exposed. In a preferred
embodiment, in the removal of a portion of the sacrificial layer 120 and
a portion of the thermosetting material layer 118, an etching method,
such as a dry etching method, may be adopted, and the portions 112b of
the transferred material layer 112 on the first portion 122 of the
sacrificial layer 120 may be used as the etching mask to etch and remove
the portion of the sacrificial layer 120 and the portion of the
thermosetting material layer 118. The dry etching method may be, for
example, a reactive ion etching (RIE) technique or an inductively coupled
plasma (ICP) ion etching technique. In some embodiments, when the dry
etching method, such as the reactive ion etching method or the
inductively coupled plasma ion etching method, is used to perform the
etching of the sacrificial layer 120 and the thermosetting material layer
118, oxygen may be used as the main reactive gas. For example, oxygen, or
oxygen and argon of specially designated ratio may be used as the etching
reactive gas. In the present exemplary embodiment, the adjacent portions
112b of the transferred material layer 112 pressed on the first portion
122 of the sacrificial layer 120 have a pitch 134.

[0020]According to the experiment discovery, the photosensitive
photoresist material is used as the etching mask to pattern the
thermosetting material layer in the conventional photolithography
technique, and the photoresist layer swells due to that the photoresist
layer absorbing a portion of the developer during the development
process, so that the volume of the photoresist layer is expanded.
Therefore, when the photoresist layer with the expanded volume is used as
the etching mask to etch the pattern of the underlying material layer,
the feature size of the formed pattern structure of the material layer is
distorted. However, in a preferred embodiment of the present invention,
the portions 112b of the transferred material layer 112 on the first
portion 122 of the sacrificial layer 120 are used as the etching mask
without using the photoresist layer as the etching mask, and the
transferred material layer 112 does not experience the exposing and
developing process, so that the transferred material layer 112 will not
swell due to the developer. Therefore, by using the transferred material
layer 112 as the dry etching mask, it can ensure that the pattern
structures of the etched sacrificial layer 120 and the thermosetting
material layer 118 are not distorted to greatly increase the fidelity of
the achieved pattern structures of the sacrificial layer 120 and the
thermosetting material layer 1118.

[0021]Then, referring to FIG. 1G, a stripping tank 128 that can resist the
etching of the stripper 130 is provided, wherein the stripping tank 128
is filled with the stripper 130 for the wet stripping step. Next, the
substrate 114, and the portions 112b of the transferred material layer
112, the first portion 122 of the sacrificial layer 120 and the first
portion 126 of the thermosetting material layer 118 on the substrate 114
are entirely immersed in the stripper 130 in the stripping tank 128 to
use the stripper 130 to completely etch and remove the first portion 122
of the sacrificial layer 120 and to lift off the portions 112b of the
transferred material layer 112 on the first portion 122 of the
sacrificial layer 122 while the thermosetting material layer 118 may
hardly be etched by the stripper 130. Therefore, the etching rate of the
stripper 130 to the first portion 122 of the sacrificial layer 120 must
be far larger than that of the stripper 130 to the first portion 126 of
the thermosetting material layer 118. In one embodiment, the ratio of the
etching rate of the stripper 130 to the sacrificial layer 120 to the
etching rate of the stripper 130 to the thermosetting material layer 118
may be, for example, larger than or equal to 30, more preferably be
larger than or equal to 40, and further more preferably be larger than or
equal to 50.

[0022]In a preferred embodiment, the thermosetting material layer 118 may
be composed of, for example, RN-1349 polyimide provided by Nissan
Chemical Industries, the sacrificial layer 120 may be composed of, for
example, PMMA, such as PMMA 950K A6 provided by MicroChem Corp., Newton,
Mass., U.S.A., and the stripper 130 may be composed of TAIMAX acetone
provided by Taiwan Maxwave Co., Ltd. In another preferred embodiment, the
thermosetting material layer 118 may be RN-1349 polyimide provided by
Nissan Chemical Industries, the sacrificial layer 120 may be photoresist
S1818 provided by Shipley Company, L.L.C., Marlborough, Mass., U.S.A.,
and the stripper 130 may be acetone, such as TAIMAX acetone provided by
Taiwan Maxwave Co., Ltd. After the etching of the first portion 122 of
the sacrificial layer 120 is completed, the substrate 114 and the first
portion 126 of the thermosetting material layer 118 on the substrate 114
are removed from the stripping tank 128 and are rinsed with the deionized
water, and then a heating and baking treatment is performed to bake under
substantially 100° C. for substantially three minutes. The first
portion 126 of the thermosetting material layer 118 remained on the
substrate 114 is the pattern structure 132 with the desired pattern, and
the pattern of the pattern structure 132 are completely and reliably
transferred from the pattern of the pattern stricture 104 of the mold
100.

[0023]The etching rate of the stripper 130 to the thermosetting material
layer 118 is very small, and the etching rate of the stripper 130 to the
sacrificial layer 120 is much larger than that of the stripper 130 to the
thermosetting material layer 118, so that the sacrificial layer 120 can
be completely etched by the stripper 130 in a very short time. Therefore,
when the sacrificial layer 120 has been completely removed by the
stripper 130, the first portion 126 of the thermosetting material layer
118 is hardly etched by the stripper 130 and is almost retained entirely,
so as to precisely and exactly transfer the pattern of the pattern
structure 104 of the mold 100 to the thermosetting material layer 118 to
obtain the pattern structure 132 with the desired pattern. Accordingly,
the pattern of the imprint mold 100 can be reliably transferred to the
thermosetting material layer 118 with low thermal budget. Therefore, the
fidelity and the reliability of the pattern transferred from the mold 100
to the thermosetting material layer 118 can be increased, and the process
cost can be greatly reduced due to the decrease of the thermal budget.

[0024]According to the aforementioned embodiments of the present
invention, one advantage of the present invention is that an imprint
process of a thermosetting material of the present invention can
accurately transfer a pattern on an imprint mold to a thermosetting
material layer, thereby effectively increasing the accuracy and the
reliability of the pattern transferred to the thermosetting material
layer. Furthermore, the imprint process can be completed under the
relatively lower temperature compared with the hot embossing nanoimprint
process, so that the remaining thermal stress formed on the substrate and
the thermosetting material layer due to high temperature can be
decreased, and the substrate and the thermosetting material layer can be
prevented from being damaged.

[0025]According to the aforementioned embodiments of the present
invention, another advantage of the present invention is that an imprint
process of a thermosetting material of the present invention can
successively define the pattern of the thermosetting material with low
thermal budget, thereby reducing the process cost and preventing the
feature size of the transferred pattern of the thermosetting material
from being distorted.

[0026]As is understood by a person skilled in the art, the foregoing
preferred embodiments of the present invention are illustrated of the
present invention rather than limiting of the present invention. It is
intended to cover various modifications and similar arrangements included
within the spirit and scope of the appended claims, the scope of which
should be accorded the broadest interpretation so as to encompass all
such modifications and similar structure.